Firing-door-controlled forced-draft blower for steam-boiler furnaces.



E. R. MULGHAHEY. FIRING DOOR CONTROLLED FORGED DRAFT BLOWER FOR STEAM BOILER FURNACES.

APPLICATION FILED MAR. 26, 1912. 1,090,820.

Patented Mar. 17, 1914.

WITNESSES:

INVENTOR Earl RMu hahe y.

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EARL It. MULGI-IAHEY, 0F PROVIDENCE, RHODE ISLAND, AS SIGNOR T0 DRAFT REG-IT'- LATOECOMPANY, OF PROVIDENCE, RHODE ISLAND, A CORPORATION OF MAINE.

FIRING-DOOR-CON'IROLLED FORCED-DRAFT BLOWER FOR STEAM-BOILER FURNACES.

Specification of Letters Patent.

7 Patented Mar. 1'7, 1914.

Application filed March 26, 1912. Serial No. 686,340.

T 0 all whom it may concern Be it known that I, EARL R. MULOHAHEY, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Firing Door-Controlled Forced-Draft Blowers for team-Boiler Furnaces, of which the following is a specification.

This invention relates to means connected to the firing door for automatically cutting ofi or controlling the volume of air introduceable into the furnaces of steam boilers through the medium of steam blowers connected with the furnaces, and it consists in the novel construction and arrangement of parts, as hereinafter set forth and claimed.

The object sought to be attained is primarily to provide the pressure-blower of a steam-boiler furnace with means connected therewith and with the firingdoor of the furnace, whereby the act of opening said door, as in charging the furnace with fuel, also acts to cut off altogether or to vary the volume of steam and air issuing from the blower; the latter thereby remaining in a temporarily inoperative condition while the door is open. The act of closing the firingdoor causes the steain-blower to resume its normal working, 2'. 6., to again serve as a force-draft appliance. It may be added thatthe means employed for controlling the blower or auxiliary draft-device used is not dependent for its action upon the varying pressure of the steam or upon its temperature, nor does the device control the movements of the fine or supplemental damper; this latter is or may be fixed or manually adjusted with respect to the normal steam required. The main flue or chimney damper and also said supplemental damper are not represented in the drawings, since they are not combined or associated with or dependent'upon the present invention for control ling the degree of flue openings.

In the accompanying drawings, Figure 1 represents a partial front elevation of a steam-boiler furnace embodying my improvement, the parts being in the normal working condition; Fig. 2 is a corresponding top plan view, portions, however, being omitted; Fig. 3 is a partial side view, the blower being in action; Fig. 4c is a front view, showing the firing-door open; Fig. 5 is a corresponding top plan View, portions disposed lever Z connected thereto.

being omitted; Fig. 6 is a partial side view, showlng the firing-door open; and Fig. 7 is a detail plan view, in enlarged scale, showmg portions of the firing-door connection in the closed condition.

The boiler front and setting are designated by the letter A, while B and C indicate the firing-door and ash-pit door, respectively. A steam pressure-blower D of suitable construction extends into the furnace, and is adapted to be normally actuated by steam from the boiler, or other source of supply, via steam pipe 6 and interposed steam valve a having a movable valve proper v. To the latter is secured a vertically guided stem 12 having a horizontally The outer or air-intake end of the blower D may consist of a fixed disk-like head having radiating circularly spaced alternating bars and openings 8 and 8 respectively; to the center of said head is movably fulcrumed a register-valve N of usual construction hav ing corresponding bars and openings 8, 8 Obviously, when the openings of the two disks are uncovered or registering with one another, the air inlet passages of the blower are normally open, and are normally closed when the valve N is swung a short angular distance in the opposite direction to cover the head openings.

The angular movements of the valve N are automatically cont-rolled by suitably mounted members m, m m m the former, 712-, being in direct connection with the steamvalve lever Z, and the latter, m jointed to the member N. Thus, it is apparent that the act of swinging the lever upward, as in opening the steam-valve o, simultaneously uncovers or opens the air-inlet passages of the blower for normal action. That is, the air of the forced draft appliance is discharged into the ash-pit under the grate; the ash-pit door obviously then being closed. See corresponding condition of the ash-pit door C as shown in Figs. 1, 2 and 3. Obviously, a contrary movement of the parts acts to close the steam and air-valves, thereby rendering them m'Z. See Figs. 4:, 5, and'6.

Now, in order to automatically effect the foregoing changes in controlling the artifieial draft appliance by the movements of the firing-door, as in opening and closing it, a link 6 is suitably jointed to the door 13 at c, the opposite end of the link being jointed to the free end of a crank-arm c, in turn pivoted at c to a stand or bracket d, preferably fixed to the front side of the boiler setting. An independently movable arm (Z is also pivoted at 0 to the outer end of arm (Z is jointed the upper end of a rod (Z its lower end being joint-connected to said valve-lever Z. To the arm 0, and movable with it, is connected an arc-shaped member 0 adapted to move angularly in an opening therefor formed in the arm (Z Thus, it will be seen that the act of opening the door B, as in firing, not only forcibly depresses the lever Z and closes the steam-valve, thereby automatically cutting off the supply of steam to the blower, but at the same time also shuts off the supply of outer air to the blower, thus rendering the latter inoperative or inert while the firing-door remains open. The act of closing the firing-door will, on the contrary, automatically and simultaneously open the steam and air valves 'v and N, respectively, thereby causing the force-draft blower to resume its normal function.

The act of swinging open the firing-door to'its normal extent, assuming the forcedraft blower to be in normal operation,'may involve a materially greater degree of angular movement than is necessary or desirable 'to impart to the valve-operating lever Z, therefore certain members of the device are constructed so as to work idly or with a degree of lost motion. That is to say, the bent member 0 of the arm 0 may move freely with the latter while the door is being opened, say more or less, at which instant the continued opening movement of the door causes the member 0 to engage the arm 6Z1, connected by a link (Z to the latter and to the valve-lever, and force the latter downward, thereby temporarily closing the steam-valve 4) against the entrance of steam into the blower, the condition then being substantially as indicated in Fig. 4. The act also closes the air-valve N at the same time. Owing to the novel construction of the ele ments connecting the forced-draft mechanism with the firing-door the latter may be opened temporarily some 50 to 60 without materially affecting the normal action of the mechanical or artificial draft upon the fuelcombustion, assuming the flue-damper to have been previously set or adjusted. The idle or delayed action thus obtained may be utilized by the fireman in cleaning the Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

grates, breaking up the fire-bed, &c. In closing the door, after firing, themaj or portion of the movement first takes up the said lost I ing readily and quickly installed, and also easily and positively actuated. I 7

Obviously, changes or modifications in the construction and arrangement of the parts may be made therein without departing from the spirit and scope of the invention.

By means of my improvement the normal forced draft air and steam are automatically prevented from entering the furnace while the firing door remains open, thus not only preventing draft action and its cooling effect upon the fire and flue, but positively preventing flare back or backdraft through'the firing opening, the advantageous result being to materially reduce coal consumption, thus increasing the boilers efliciency.

I claim: 7

In a steam boiler furnace, the combination of a normally open steam valve arranged to receive a supply of steam from the boiler,

means connected with said valve and with the fire door of the furnace arranged to close the valve upon opening said door, as in firing, a forced draft blower connected to and normally actuated by said valve,'said blower having a controlled air inlet, means con-.

nected with an element of said valveactuating device arranged to automatically out off the supply of air to said blower simultaneously with the closing of the steam supply valve, and means arranged to open the re spective air and steam passages to cause an inflow of steam and air into the blower con currently with the act of closing the fire door, substantially as described.

In testimony whereof I have aifixed signature in presence oftwo witnesses.

EARL R. MULGHAHEY.

Witnesses:

GEO. H. REMINGTON, CALVIN H. BROWN.

Washington, D. G.

consequent 

